[ Ref. "Seek Pressure & Vacuum Pump Units for Calliope", by
 [ Gene Calman, in 141216 MMDigest.  -- Robbie

We built my blower and vacuum units in two separate boxes.  For the
blower motor I purchased a used one on eBay that was from a carpet
shampooer (3 stage IIRC).  I really have to slow it down, and I use
a router speed control because of the current it draws.  Even then
I put a heat sink on the back of the controller.

The vacuum unit uses a sweeper motor from a junked Hoover "Wind
Tunnel".  Again, I have to really slow it down, but get by using
a cheap fan speed controller.  I don't need a lot of vacuum because
my roll player uses a DC motor instead of a vacuum motor.  But the
Rewind/Play mechanism doesn't always work reliably under the lower
vacuum levels (it also needs some work on the pneumatics).

I'm sorry I can't give specific references to the motors used because
they were salvaged, and it's been three or four years.  I'd have to
take the boxes apart to see if there are any part numbers, but it is
way too cold to work on this at this time of the year.

I do believe both of my motors were "overkill", based upon how much I
slow them down, but the advantage is that the noise is greatly reduced.
Of course these were both "universal" type of motors that use brushes,
so they can be slowed down by varying the AC voltage.  We also tried
to build in noise reduction (baffle and sound-deadening material) as
we built the boxes.

My shop friend and I are both somewhat hobbyists, certainly not pros
regarding this.  I did a lot of questioning and researching.  It was
quite a learning experience.  MMD and Robbie and the Internet were
invaluable.

Larry Claus